Purling device for buttonhole-sewing machines.



D. NOBLE & J. s. FINCHQ FUELING DEVICE FOR BUTTONHOLE SEWING MACHINES.

APPLICATION FILED DEC. 19, 190. I

Patented. May 4, 1909.

2 SHEETS-SHEET 2 001mm 10 915 AN JOHN THEIR ATTORNEY- DONALD NOBLE AND JOHN ASSIGNMENTS, To THE SINGER JERSEY.

s. FIN on, or BRIDGEPORT, conrrorico'r, ASSlGNORS, BY nnsrn iNIANUFACTURlNG conrinxr, A. GORPORA'llON or NEW FUELING DEVICE FOR BUTTONIIOLE-SEWING MACHINES.

Specification of Letters Patent.

Patented May 4, 1909.

Application filed December 19, 1906. Serial No. 348,620.

. To all whom "it may concern:

Be it known that we, DONALD NOBLE, a

- subject of the King of Great Britain, and

'in connection with buttonhole sewing ma- ,OhlIlQS where n 1t 1s desired to iorm'and posipresser, and so arranged and JOHN S. Fmcn, a citizen of the United States, residents of Bridgeport, in the county of Fairfield and State of Connecticut, have invented certain new and useful Im l rovements in Purling Devices for Buttonole-Sewing Machines, of which the follow- 3 ing is a specification.

Our. invention relates to certain new and useful improvements in sewing machines for making buttonholes and has especial refer-, ence to the means employed for effecting purl stitching.

Our invention is especially adapted for use i tion the so-called purl stitching on the opposite edges of the buttonhole slit, thereby giving tothe finished buttonholethe appearance of hand overseaming. It is well understood that purl stitching is effected by ositioning the locks of the in an unbroken line.

Our invention consists in equipping such a .machine with a purling device comprising a purling footprovided with a needle opening and adapted ,to rest upon the material within .the space inclosed by the cloth-gripping constructed as to partake of allthe motions oi the latter, except the feed movements lengthwise of the buttonhole, and provided with walls for ena g the lock of the sewmg threads as such Foo is set-or tightened by the action of the take-up for the formation of the stitch.

In the accompanying drawings which form a part of thisspecific'ation and in whichlike arts are similarly designated throughout t lie several views, Figure 1 is'an end elevation of a buttonhole sewing machine equipped with our improvement. Fig. 2 is a rear side elevation of a portion of the front end of the overhanging arm illustrating, particularly in connection with Fig. 1, how the purlin device is held against turning. Fig. 3 is a detail perspective view of a portion of the cloth clamp, together with our improved purlin device and its connections, detached from t lie machine. Fig. 4 is a sectional elevation, partially broken, taken on the line X, X, of Fig. 3. Fig.5 is anenlargedhor1-' 1 i l l l l sewing threads 1 j the bottom larged bottom view of the purling foot. 9 is an enlarged rear elevation 01' the purling foot, as seen from, the bottom edge of Fig. 8."

, machine as is zontal section or plan view taken'on the line.

Y, Y, of Fig. 4. Fig. 6 is.a view similar to Fig. 5, but illustrating the stitch formation on the opposite or right tonholei Fig. 7 is an enlarged front edge elevation of the purling foot, as' seen from edge of Fig. 5: Fig. 8 is an en- Fig.

Fig; 10 is anenlarged detail perspective ol the purling foot as viewed from the top side thereof. Fig. 11 is an enlarged detail per spective view otthe purling foot, as seen when inverted.

In describing our improvements, only such limited reference will be made to the usual hand side of the but' well-known parts of the butto'nhole sewing deemed necessary for a proper understanding of our invention.

1 is the base of the machine surmounted by the usual overhanging arm 2.

3 is the throat-plate and 4 and 5 are the 11 per and lower members, respectively, of the cloth-clamp, which clamp ismounted upon the cloth clamp slide 6, the latter being actuated in the usual or any approved manner to present the material to the action-of the stitch-forming mechanism. The clothclamp member 4 is provided with a suitable cloth-gripping presser 7 and with the usual.

opening 8 through which the needle 9 passes in forming the stitch. Secured in the. end of the overhanging arm 2, directly back of the needle-bar 10, is a bushing 11 within which is slidably mounted a presser-bar 12, to the upper end of which latter is secured a collar 13 having formed thereon an arm 1 1 projecting within a vertical slot 15 cut in the rear of the arm 2, by means of which said presser-bar is held against'turning in the bushing within which it slides.

, one end of which is secured to the underside of the collar 13, while the other end is secured at 17 within the hollow end of the arm.;2, by means of which said 16 is a coil spring,

presser-bar and parts carried thereby are,

pressed resiliently downward to engage the materiaLv 3 Formed on the lower end of the presser-bar 12 is a horizontally disposedsocket 18 within which is pivoted a short shaft 19 formed on the upper end of an arm 20, a collar 21 on the end of said shaft servin to hold the latter in position within the soc et. Projecting laterally from the sides of the arm 26, near the bottom thereof, are lugs 22, .22, adapted to engage the parallel edges 23, 23 of'the clothclamp member 4, whereby when the latter is raised to adjust the material, the arm 20 will also be lifted, as will be readily understood. The arm 20 is prowded at its lower end witha purling foot 24 which also acts as a cloth presser, and is of'approximately the same width as the opening 8 in the cloth-gripping presser 7, said foot depending within said opening-8 to'engage the material, and as thecloth-clamp is vibrated jtr'ansversely to the with the needle, is of a peculiar shape, being a length of the opening in; said clamp, the foot 24 will-also partake of such vibration, as will I be apparent by referenceto Figs. 1,3 and 4. The needle aperture 26 in the purling foot 24, which, of course, is in proper alinement wide enough to accommodate the lateral vibrations of thecloth-clamp for oversea-ming both sides of the buttonhole. The foot 24 is provided with walls 26, 27', against which the locks of the o'versearn stitches are held when the take-up is actuated to tighten or set the stitch. The bottom of the foot 24 is chamfered or relieved, as shownat 28, 29,

= stitches, supposing that the overseaming of so that only a portion ofsu ch: surface will bear upon the material when forming the stitches. 1

In the formation of the side oversearn the left hand side 30 is-first presented to the unbroken line, the long loops being indicatedaction of the stitch-forming mechanism, the material will be fed in the direction indicated by the arrow '31; while in overseaming the second or right hand side 32, thematerial will be fed in the opposite direction, as indicated by the arrow 33. As is well known,

this peculiar. form of overseam for buttonholes is composed of alternate long and short loops of. bobbin thread, the locks of which aredrawn by the upper thread to form an by 34, the short loopsby 35, and the upper thread by 36. As shown in'FigsL 5 and 6,

- the long loops are drawn ata somewhat acute angle, but the setting or tighteningdf the succeeding stitch which is'a short loop,

causes the long loops to be positioned as seen in the other portions of these figures. The slot 37, made at the rear of-the foot 24, provides for the use of a knifefor cutting the buttonhole slit, as clearly shownin the drawings. Referring more particularly to Figs. 5 and 6, the walls 26, 27 are arranged on opposite 3 sides of the longitudinal center ofthe buttonneedle is ready to descend through thebuttonhole slit at 38 intheformation or an edge hole slit and on opposite sides of a line inter secting the line of verticalrnovements oi the needle and transversely to, the hne of iced. Supposing the oversearning' to have progressed as illustrated in Fig. 5,, whereinthe stitch, as the needle is moving to its highest;

position in the formation of such edge stitch,

the cloth -clamp is vibrated to the right to position the material for the next subsequent.

stitch, which is a depth stitch, and at the same time the clamphas advanced the material in the direction indicated by the arrow 31, to a position which brings the stitchformi ng position 38 to the position previously occupied by stitch 39, or in contact with wall 26. v1t 18 to be observed that the overseaming stitch 40 leads from the depth stitch to the line of edge stitches, and is drawn to such position by the take-up before the needle descends to form the edge stitch positioned at 38, and during the time that the take-up is returning, to its lowest position and again to 'theposition for setting the edgestitch at 38,

the overseam stitch 40 lies loosely upon the material. rThe formation and tightening of the edge stitch anehorsthe inner end of the long overseam stitch and positions such overseam stitch at right angles to the buttonhole slit, as illustrated by stitches 3.4 and 35; and

such stitch formation and feed are con tinued to the finishing of the si'd'eoverseaming, -thus positioni the lock stitch. y

. When overseaming the right-hand side of the buttonhole, as represented by Fig.6, the purl is controlled by thewall 27 in the same manner as the wall 26'controls the left hand side of theoverseaming, .Fig. 5. In Fig.5

' the edge stitch 39' is advanced farther than n of each edge stitch opposite of 'the wall 26 before the take-. u sets or tightens the succeeding edge the corresponding stitch 41, (Fig. 6) t0 illustrate-that when using a-very fine feed, as fine as is practical for general manufacturing, the feed movement willca rry the 'stitcb ll only.- slightly beyond the corner-42 the walls 7 4'3; 43 are: offset from. the walls 44,- 44 a dis,-

tanc'e only slightly greater thanthe' diameter of-the needle; and in actual construction, the purling foot is onlyabout one-fourth" of an. inch wide, outside'measurement. To better facilitate the feeding of theoverseam stitches beneath the purling foot, the corners 42 and 45, at their lower ends, are slightly beveled, see Fig. 11'. The cha'miering or cutting away of. the underside of the foot as at 28, 29

is done, as previously stated, to give less bearing surface, so that the lower edge of the walls 26', 27 will bear more directly upoii th I material. .46 is the clamp closing lever pivoted on the post 47' andiormed with acam portion 48 which bears upon a spring washer our'patent application for Buttonhole sewing machine filed under even date herewith, which-application comprises the. con-' struction of .buttonhole sewing machine to 5 which our present invention is applied, and to which reference may be had for a more definite understanding of such features of 1 construction as are herein shown but not de- In a purling device for buttonliole sewing" machines, a cloth-clamp. provided with a cloth-grip ing presser having an opening through w ich the edges 'of the buttonhole 7 20 are oversearned, a purling foot depending a needle opening in said foot'formed with olp within said opening to engage the material,

positely arrangedofi'set. lock-guiding w s forvthe respective'sides of the buttonho'le,--

against which the locks of the sewing 25 threads are positioned u on the material and held .in line, a resilient y mounted pr'esserbar, to the lower end of which ispivoted an' arm to move transversely to the line of feed,

and upon the lower end of which said foot is 30 forme J a Signed atiBridgepor-t, in the county of- F airfield, and State of Connecticut, this 18th day of Dece1nber,'A. 1906.

DONALD "NOBLE. v I JOHN S. FINOH.

l/Vitnesses:

' A. K. l/VILLIAMS, Jr.,'

W. G. MARKs. 

